The study on lung injury of minipigs' right-thorax with a single high-dose γ-ray irradiation / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the influence and mechanism of cytokines and protein expression of alveolar epithelial type (ACE) Ⅱ cells in Bama minipigs' right-thorax with a single 15 Gy dose irradiation.Methods All minipigs received either right thoracic irradiation or sham-irradiation under anesthesia.At 4,8,12 and 24 week post-irradiation,5 minipigs respective and random from irradiarion groups and control group were sacrificed to remove the lungs.The protein expression of surfactant associated protein (SP)-A,transforming growth factor (TGF)-β1,Vimentin and E-cadherin were detected by Western blot.The protein expression of α-smooth muscle actin (SMA) was detected by immunohistochemistry.The co-localization of SP-A and α-SMA was visualized by double immunofluorescence staining.Results At 4,8,12 and 24 week post-irradiation,a significant increase in the protein expression of α-SMA,TGF-β1 and Vimentin were observed in irradiated lung compared to sham-irradiated controls(α-SMAt =2.46-3.26,P ＜0.05;TGF-β1t =2.96-3.52,P ＜0.05;Vimentint =3.24-5.05,P ＜ 0.05).By contrast,the protein expression of SP-A and E-cadherin in irradiation group was lower than it in control group (SP-At =3.62-4.65,P ＜ 0.05;E-cadherint =2.53-4.15,P ＜ 0.05).Moreover,at 8 week after irradiation,under confocal laser scanning microscope,the co-localization of SP-A and α-SMA was observed in irradiated alveolar epithelium cells,and it was not observed in sham-irradiated controls.Conclusions These data demonstrate that E-cadherin,SP-A and TGF-β1 may act as sensitive predictors of radiation-induced lung injury(RILI).Irradiation may lead to ACE Ⅱ cells achieving a mesenchymal phenotype,namely,epithelial to mesenchymal cells transition occurs,and ACE Ⅱ cells play the important part in the development of RILI by epithelial-mesenchymal transition.